Method and apparatus for packaging surface acoustic wave transponder for down-hole applications

Abstract

A method and apparatus for packaging a surface acoustic wave transponder for use in harsh environments is provided. An exemplary transponder comprises a surface acoustic wave piezoelectric device, wire bonds, an antenna element, an antenna substrate, a dome structure, and casing. The exemplary surface acoustic wave piezoelectric device is attached directly onto the antenna substrate and wire bonded to an antenna element. The surface acoustic wave piezoelectric device is protected under the dome structure, which is sealed and attached to the antenna substrate. The components are encased and sealed within a transponder casing. The transponder may be part of or incorporated into substantially any shape or form factor.

What is claimed is: 
     
       1. A tagging transponder device comprising:
 a surface acoustic wave (SAW) piezoelectric device bonded directly onto a bottom surface of an antenna substrate by a first bonding agent configured to maintain the bond within a temperature range of −67° F. to 662° F.; 
 a dome enclosure positioned over the SAW piezoelectric device, the dome enclosure having a bottom dome edge hermetically sealed with a second bonding agent to the bottom surface of the antenna substrate such that the SAW piezoelectric device is hermetically encased within the dome enclosure and the bottom surface of the antenna substrate, the second bonding agent configured to maintain the hermetic seal between the bottom dome edge and the bottom surface over the temperature range of −67° F. to 662° F.; 
 a predetermined gas being about the SAW piezoelectric device, the predetermined gas being hermetically encased within the dome enclosure and the bottom surface of the antenna substrate, the predetermined gas being selected from a group consisting of helium, nitrogen and other gases comprising similar minimal expansion characteristics over the temperature range of −67° F. to 662° F.; 
 an antenna layer covering a substantial portion of a top surface of the antenna substrate; 
 an electrical connection extending from the SAW piezoelectric device, through a via in the antenna substrate and to a portion of the antenna layer, wherein the via is hermetically sealed with a sealing compound such that the gas does not escape from about the SAW piezoelectric device; and 
 an outer radio frequency transparent potting material substantially covering the top surface and the bottom surface of antenna substrate as well as the dome enclosure and the antenna layer. 
 
     
     
       2. The device of  claim 1 , wherein the tagging transponder device is configured to be incorporated into a plurality of tag form factors adapted to anchor hold the tagging transponder device to a solid asset or object being tagged. 
     
     
       3. The device of  claim 1 , wherein the antenna layer comprises an antenna electrical connection portion positioned on the top surface of the antenna substrate directly opposite to the dome enclosure. 
     
     
       4. The device of  claim 1 , wherein the dome enclosure is a radome that is substantially transparent to radio frequencies in the range of 2.45 GHz +/−50 MHz. 
     
     
       5. The device of  claim 1 , wherein the dome enclosure is conductive. 
     
     
       6. The device of  claim 1 , further comprising a ground plane positioned on the bottom surface of the antenna substrate and about the dome enclosure. 
     
     
       7. The device of  claim 5 , wherein the dome enclosure is in conductive contact with a ground plane positioned on the bottom surface of the antenna substrate. 
     
     
       8. The device of  claim 1 , further comprising a ground plane positioned on the bottom surface of the antenna substrate. 
     
     
       9. The device of  claim 1 , wherein the SAW piezoelectric device comprises delay lines positioned to uniquely identify the tagging transponder to SAW interrogator device. 
     
     
       10. A tagging transponder device comprising:
 an antenna substrate having a top surface and a bottom surface; 
 an antenna layer covering a substantial portion of the top surface, the antenna layer comprising an antenna electrical connection portion; 
 at least one via extending from the antenna electrical connection portion through the antenna substrate to the bottom surface of the antenna substrate; 
 a surface acoustic wave (SAW) identification device bonded with a first high temperature bonding agent directly to the bottom surface of the antenna substrate adjacent to the at least one via, the SAW identification device comprising at least one bonding wire, the boding wire being electrically connected through the via to the antenna electrical connection portion, the via being hermetically sealed with a hermetic sealing material; 
 a dome enclosure covering the SAW identification device, the dome enclosure comprising a bottom edge hermetically sealed with a bonding agent against the bottom surface, the bonding agent comprising an epoxy or resin configured to maintain the hermetic seal between the bottom edge and the bottom surface throughout a temperature range of −67° F. to 662° F.; and 
 a gas, selected from a group consisting of nitrogen and helium, being contained and hermetically sealed between the dome enclosure and the bottom surface. 
 
     
     
       11. The device of  claim 10 , further comprising a ground plane on the bottom surface and about the dome enclosure. 
     
     
       12. The device of  claim 10 , wherein the dome enclosure is made of a conductive material and is hermetically sealed against the bottom surface with the bonding agent, wherein the bonding agent further comprises conductive material. 
     
     
       13. The device of  claim 12 , further comprising a ground plane on the bottom surface, the ground plane being conductively connected to the dome enclosure through the bonding agent. 
     
     
       14. The device of  claim 10 , wherein the dome enclosure is substantially transparent to radio frequencies in the range of 2.45 GHz +/−50 MHz. 
     
     
       15. The device of  claim 10 , further comprising a radio frequency transparent potting material that covers the top surface and the antenna layer as well as the bottom surface and the dome enclosure. 
     
     
       16. The device of  claim 15 , being configured for incorporation into a tag form factor that is configured to anchor or hold the tagging transponder to a solid asset or object being tagged. 
     
     
       17. A tagging transponder device comprising:
 an antenna substrate comprising a top surface and a bottom surface; 
 a first antenna comprising a first electrical connection on the top surface of the antenna substrate; 
 a second antenna comprising a second electrical connection on the top surface of the antenna substrate, the first electrical connection being proximate to the second electrical connection; 
 a SAW tagging device comprising a first connection wire and a second connection wire, the SAW tagging device being bonded with a first bonding agent to the bottom surface of the antenna substrate, the first bonding agent being a high strength adhesive comprising epoxy or resin configured to maintain a bond from −67° F. to 662° F.; 
 a first via extending through the antenna substrate, the first via being proximate to and electrically connected to the first connection wire, the first via further being electrically connected to the first electrical connection of the first antenna portion, the first via being filled with a hermetically sealing compound configured to hermetically seal the first via; 
 a second via extending through the antenna substrate, the second via being proximate to and electrically connected to the second electrical connection of the second antenna portion, the second via being filled with the hermetically sealing compound configured to hermetically seal the second via; 
 a dome structure covering the SAW tagging device, the first via and the second via, the dome structure having a bottom edge that is bonded with a second bonding agent to the bottom surface of the antenna substrate, the second bonding agent hermetically sealing the bottom edge to the bottom surface, the second bonding agent comprising an epoxy or resin configured to maintain the hermetic seal between the bottom edge and the bottom surface throughout a temperature range of −67° F. to 662° F.; and 
 a predetermined gas selected from a group consisting of nitrogen and helium, the predetermined gas being hermetically sealed between the dome structure and the antenna substrate. 
 
     
     
       18. The device of  claim 17 , further comprising a ground plane on the bottom surface of the antenna substrate.